Dear ransomware authors, Thank you! No joking, no saltiness, no BS. You may think this is in jest, but I whole-heartedly want to say ‘thank you.’ I’ve been around security long enough to see *many* turn the corner from “we’ll get to security when we get to it” to genuinely being interested in improving. I cannot begin to describe how disheartening it is to do back-to-back yearly security assessments for a bank [or countless other businesses] and have the same…

HL7 Data Interfaces in Medical Environments – Attacking & Defending the Achilles’ Heel of Healthcare This security research served as a 2-part SANS gold paper examining the insecurities of the HL7 messaging standard. This presentation is a combination of those two papers. HL7 is arguably the most fundamental flaw in healthcare IT. It is used extensively for system-to-system communications and is in nearly every healthcare facility worldwide. The first paper is an overview of what can be done with stolen…

In this walkthrough, I will show how to install and test the pi-hole on Ubuntu and more specifically, Ubuntu Server. Why Ubuntu instead of a Raspberry Pi? I love Raspberry Pis and I probably own at least 10 of them. But sometimes I want to perform DNS blocking/blackholing and I either a) don’t have a Raspberry Pi in an environment or b) I have a virtual environment where I can add some robustness to the solution. Changelog 24July2018 – Originally posted…

What is this traffic on port 8888? Or a device is infected and trying to communicate over port 8888 to IP addresses all over the world?!?! I’ve seen forum posts with similar titles a handful of times now and the final result is often someone discovering the Private Internet Access (PIA) client on a device or computer. I get a chuckle every time I see it because I was once in their shoes so I figured I would make a…

This is a walkthough for installing and configuring OpenVAS 9 on CentOS 7. OpenVAS (Open Vulnerability Assessment System) is an opensource vulnerability scanner. Brief History OpenVAS forked from Nessus when Tenable took the previously opensource product to closed source back in 2005. That’s worth mentioning primarily because on a side note, I’ve used Nessus for many years and I remember when it was forked. Since then, Nessus became one of the leaders in the vulnerability scanning space and a fairly…

This walkthrough uses the DNSBL portion of pfBlockerNG to remove ads/advertising and more importantly, malvertising. It essentially creates a functionality similar to the pi-Hole project except it doesn’t require a separate piece of hardware. Instead, you just use your pfSense + pfBlockerNG! If you’re interested in a write-up on installing/configuring the pi-hole on Ubuntu, I have one here. Please note this walkthrough is for the new devel version of pfBlockerNG. The pfBlockerNG-devel package is now in the standard list of…

We’ve all been there. Your SSL/TLS certificate on your webserver, mail server, or <insert service name here> has expired and your users are miffed!!! Expiring SSL/TLS certificates have been a problem as long as I can remember and that was at a point when SSL certs could last for several years. Now we have Let’s Encrypt (@letsencrypt) in the fray of SSL/TLS certs and their certs only last a maximum of 90 days. Do you really think expiring certs won’t…

This walkthrough uses the DNSBL portion of pfBlockerNG to remove ads/advertising and more importantly, malvertising. It essentially creates a functionality similar to the pi-Hole project except it doesn’t require a separate piece of hardware. Instead, you just use your pfSense (pfBlockerNG)! If you’re interested in a write-up on installing/configuring the pi-hole on Ubuntu, I have one here. I love pfSense and if I could only install one package to enhance its capabilities, it would undoubtedly be pfBlockerNG. pfBlockerNG is a pfSense…

Tired of seeing outbound NTP blocks in your firewall logs because you restrict outgoing traffic? Or maybe you are receiving alerts because some device uses NTP pool resources (such as pool.ntp.org) and one of those IP addresses has ended up on a blacklist, blocklist, threat intelligence feed, etc? Either way, few things in the life of an IT or security professional are as frustrating as false positives. This write-up will help you change that with a little NAT magic, aka…